WASHINGTON: President Joe Biden said Thursday after announcing sanctions against Russia that for both countries "now is the time to deescalate."

Biden described the sanctions, which are aimed at the Russian economy and dozens of individuals, as a "measured and proportionate" response to Moscow's hostile actions against the United States.

He said that during a phone call earlier this week he was "clear with President Putin that we could have gone further" but added that Washington is "not looking to kick off a cycle of escalation and conflict with Russia."

Biden said that with direct communication between him and Vladimir Putin they could establish "a more effective relationship" and that the Kremlin leader "agreed" with this.

Biden's proposed summit with Putin, which he said could take place "this summer in Europe," would be a chance to "launch a strategic stability dialogue."

Putin has not yet responded to the invitation but Biden said "our teams are discussing that possibility right now."

Biden said there were "critical global challenges that require Russia and the United States to work together, including reining in nuclear threats from Iran and North Korea, ending this (coronavirus) pandemic globally, and meeting the existential crisis of climate change."

Biden said he'd challenged Putin on Russia's invasion of part of Ukraine and current massing of troops on another part of the border.

"I affirmed US support for the sovereignty and territorial integrity of Ukraine and I strongly urged him to refrain from any military action."

However, Biden was less clear about US policy over the almost complete Nordstream 2 pipeline which is due to funnel Russian natural gas to Germany, while bypassing the existing export route through Ukraine.

There is a strong push in the United States to cripple the project with sanctions and prevent its completion, out of fear that it will give Moscow a dangerous grip on the energy supplies of US allies in Europe.

However Thursday's package of sanctions made no mention of Nordstream 2 and Biden, when asked by a reporter, said it was "a complicated issue."

"That still is an issue that is in play," he added, without further explanation.